1. Field of the Invention
The present invention relates to an improvement of a tool changer for a welding robot which is adapted to supply electricity, gas, air, water and the like to a tool such as a welding robot gun.
2. Description of the Prior Art
A tool changer for welding robot of this type is known as illustrated in FIG. 8. The prior tool changer for welding robot will be described hereunder with reference to FIG. 8. The prior tool changer for welding robot comprises a substrate 111 connected to a welding robot arm (not shown), an absorbing plate 113 supported by the substrate 111 via piano lines 112 at three points thereof for absorbing a lateral displacement of movement thereof, a holding plate 117 supported by the absorbing plate 113 via piano lines 114 at three points thereof for holding a guide pin 115 and a connector 116 (for supplying electricity, gas, air, water), and another substrate 118 provided with female portions 119, 120 respectively for receiving the guide pin 115 and the connector 116.
With the arrangement of the prior tool changer for welding robot the other substrate 118 is moved close to the substrate 111 so that the guide pin 115 is inserted into the female portion 119 whereby the connector 116 can be inserted into the female portion 120.
There is another of this type, so-called gun changer as illustrated in FIG. 9.
The gun changer comprises a substrate 130 provided with connector 132, a substrate 131 provided with connectors 133 in confronting relation with the connectors 132 and a transformer 134 mounted at the side opposite to the connectors 133 and having secondary terminals 135, 135, a movable arm 137 which is movable by a cylinder 136 and connected to one of the secondary terminals, an arm 138 connectoed to other of the secondary terminals, the movable arm 137, the arm 138 and the cylinder 136 being laid over the transformer 134 for welding purpose via an equalizer 139. Hence, when the gun is to be changed, the whole device including the transformer at the side of the welding gun shall be replaced with another device.
However, there are following problems in the prior tool changer for welding robot.
(1) Inasmuch as the guide pin and the guide pin receiver as well as the connector have been employed in the tool changer, the tool changer has a complex construction and the guie pin has no function other than to merely guide the connector.
(2) Various connectors depending on the various purposes of the tools are provided both at the side of the tool or the welding gun and the side of the robot whereby a considerable cost, and a facility in the provision thereof are required as well as laborious and inefficient procedures for replacement thereof.
(3) In the gun changer having the transformer thereon, the gun changer is bulky as a whole, and the center of gravity is high which makes the gun changer unstable. Furthermore, since the transformer is to be changed at the state where the transformer is connected to the gun, the transformer is required to be changed for each welding gun.
It is therefore an object of the present invention to provide a tool changer for welding robot having connectors serving also as the guide pin and the guide pin receiver so that the guide pin and the guide pin receiver can be omitted to simplify the construction thereof whereby first problem set forth above (1) is overcome, hacking connectors unitized and detachably mounted on the second base on each substrate whereby the problem set forth above (2) is overcome, and having connectors disposed at both outsides of the transformer whereby the third problem set forth above (3) is overcome.
To achieve the above objects, the tool changer for welding robot comprises male portions of connectors provided at a substrate fixed to a robot arm side for supplying electricity, gas, air, water to the tool side from the robot arm side; and female portions of connectors to be connected to the male portions of the connectors and provided at a substrate fixed to a tool side for receving electricity, gas, air, water from the male portions of connectors, characterized in that one pair or plural pairs of connectors serve as both the connectors and a guide mechanism composed of a guide pin and a guide receiver.
Another tool changer for welding robot comprises male portions of connectors provided at a substrate fixed to a robot arm side for supplying electricity, gas, air, water to the tool side from the robot arm side; and female portions of connectors to be connected to the male portions of the connectors and provided at a substrate fixed to a tool side for receving electricity, gas, air, water from the male portions of connectors, characterized in that the male and the female portions of connectors are respectively unitized in the plural numbers and detachably mounted on each substrate.
Still another tool changer for welding robot comprises male portions of connectors provided at a substrate fixed to a robot arm side for supplying electricity, gas, air, water to the tool side from the robot arm side; and female portions of connectors to be connected to the male portions of the connectors and provided at a substrate fixed to a tool side for receving electricity, gas, air, water from the male portions of connectors; a transformer provided at the substrate fixed to the welding gun side and disposed between the female portion of connectors, characterized in that one or more pairs of connectors serve as both the connectors and a guide mechanism composed of a guide pin and a guide receiver.
The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings.